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-rw-r--r--fs/btrfs/extent_io.h313
1 files changed, 313 insertions, 0 deletions
diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
new file mode 100644
index 0000000000..68368ba993
--- /dev/null
+++ b/fs/btrfs/extent_io.h
@@ -0,0 +1,313 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef BTRFS_EXTENT_IO_H
+#define BTRFS_EXTENT_IO_H
+
+#include <linux/rbtree.h>
+#include <linux/refcount.h>
+#include <linux/fiemap.h>
+#include <linux/btrfs_tree.h>
+#include "compression.h"
+#include "ulist.h"
+#include "misc.h"
+
+struct btrfs_trans_handle;
+
+enum {
+ EXTENT_BUFFER_UPTODATE,
+ EXTENT_BUFFER_DIRTY,
+ EXTENT_BUFFER_CORRUPT,
+ /* this got triggered by readahead */
+ EXTENT_BUFFER_READAHEAD,
+ EXTENT_BUFFER_TREE_REF,
+ EXTENT_BUFFER_STALE,
+ EXTENT_BUFFER_WRITEBACK,
+ /* read IO error */
+ EXTENT_BUFFER_READ_ERR,
+ EXTENT_BUFFER_UNMAPPED,
+ EXTENT_BUFFER_IN_TREE,
+ /* write IO error */
+ EXTENT_BUFFER_WRITE_ERR,
+ EXTENT_BUFFER_NO_CHECK,
+ /* Indicate that extent buffer pages a being read */
+ EXTENT_BUFFER_READING,
+};
+
+/* these are flags for __process_pages_contig */
+enum {
+ ENUM_BIT(PAGE_UNLOCK),
+ /* Page starts writeback, clear dirty bit and set writeback bit */
+ ENUM_BIT(PAGE_START_WRITEBACK),
+ ENUM_BIT(PAGE_END_WRITEBACK),
+ ENUM_BIT(PAGE_SET_ORDERED),
+};
+
+/*
+ * page->private values. Every page that is controlled by the extent
+ * map has page->private set to one.
+ */
+#define EXTENT_PAGE_PRIVATE 1
+
+/*
+ * The extent buffer bitmap operations are done with byte granularity instead of
+ * word granularity for two reasons:
+ * 1. The bitmaps must be little-endian on disk.
+ * 2. Bitmap items are not guaranteed to be aligned to a word and therefore a
+ * single word in a bitmap may straddle two pages in the extent buffer.
+ */
+#define BIT_BYTE(nr) ((nr) / BITS_PER_BYTE)
+#define BYTE_MASK ((1 << BITS_PER_BYTE) - 1)
+#define BITMAP_FIRST_BYTE_MASK(start) \
+ ((BYTE_MASK << ((start) & (BITS_PER_BYTE - 1))) & BYTE_MASK)
+#define BITMAP_LAST_BYTE_MASK(nbits) \
+ (BYTE_MASK >> (-(nbits) & (BITS_PER_BYTE - 1)))
+
+struct btrfs_root;
+struct btrfs_inode;
+struct btrfs_fs_info;
+struct extent_io_tree;
+struct btrfs_tree_parent_check;
+
+int __init extent_buffer_init_cachep(void);
+void __cold extent_buffer_free_cachep(void);
+
+#define INLINE_EXTENT_BUFFER_PAGES (BTRFS_MAX_METADATA_BLOCKSIZE / PAGE_SIZE)
+struct extent_buffer {
+ u64 start;
+ unsigned long len;
+ unsigned long bflags;
+ struct btrfs_fs_info *fs_info;
+ spinlock_t refs_lock;
+ atomic_t refs;
+ int read_mirror;
+ struct rcu_head rcu_head;
+ pid_t lock_owner;
+ /* >= 0 if eb belongs to a log tree, -1 otherwise */
+ s8 log_index;
+
+ struct rw_semaphore lock;
+
+ struct page *pages[INLINE_EXTENT_BUFFER_PAGES];
+#ifdef CONFIG_BTRFS_DEBUG
+ struct list_head leak_list;
+#endif
+};
+
+struct btrfs_eb_write_context {
+ struct writeback_control *wbc;
+ struct extent_buffer *eb;
+ /* Block group @eb resides in. Only used for zoned mode. */
+ struct btrfs_block_group *zoned_bg;
+};
+
+/*
+ * Get the correct offset inside the page of extent buffer.
+ *
+ * @eb: target extent buffer
+ * @start: offset inside the extent buffer
+ *
+ * Will handle both sectorsize == PAGE_SIZE and sectorsize < PAGE_SIZE cases.
+ */
+static inline size_t get_eb_offset_in_page(const struct extent_buffer *eb,
+ unsigned long offset)
+{
+ /*
+ * For sectorsize == PAGE_SIZE case, eb->start will always be aligned
+ * to PAGE_SIZE, thus adding it won't cause any difference.
+ *
+ * For sectorsize < PAGE_SIZE, we must only read the data that belongs
+ * to the eb, thus we have to take the eb->start into consideration.
+ */
+ return offset_in_page(offset + eb->start);
+}
+
+static inline unsigned long get_eb_page_index(unsigned long offset)
+{
+ /*
+ * For sectorsize == PAGE_SIZE case, plain >> PAGE_SHIFT is enough.
+ *
+ * For sectorsize < PAGE_SIZE case, we only support 64K PAGE_SIZE,
+ * and have ensured that all tree blocks are contained in one page,
+ * thus we always get index == 0.
+ */
+ return offset >> PAGE_SHIFT;
+}
+
+/*
+ * Structure to record how many bytes and which ranges are set/cleared
+ */
+struct extent_changeset {
+ /* How many bytes are set/cleared in this operation */
+ u64 bytes_changed;
+
+ /* Changed ranges */
+ struct ulist range_changed;
+};
+
+static inline void extent_changeset_init(struct extent_changeset *changeset)
+{
+ changeset->bytes_changed = 0;
+ ulist_init(&changeset->range_changed);
+}
+
+static inline struct extent_changeset *extent_changeset_alloc(void)
+{
+ struct extent_changeset *ret;
+
+ ret = kmalloc(sizeof(*ret), GFP_KERNEL);
+ if (!ret)
+ return NULL;
+
+ extent_changeset_init(ret);
+ return ret;
+}
+
+static inline void extent_changeset_release(struct extent_changeset *changeset)
+{
+ if (!changeset)
+ return;
+ changeset->bytes_changed = 0;
+ ulist_release(&changeset->range_changed);
+}
+
+static inline void extent_changeset_free(struct extent_changeset *changeset)
+{
+ if (!changeset)
+ return;
+ extent_changeset_release(changeset);
+ kfree(changeset);
+}
+
+struct extent_map_tree;
+
+int try_release_extent_mapping(struct page *page, gfp_t mask);
+int try_release_extent_buffer(struct page *page);
+
+int btrfs_read_folio(struct file *file, struct folio *folio);
+void extent_write_locked_range(struct inode *inode, struct page *locked_page,
+ u64 start, u64 end, struct writeback_control *wbc,
+ bool pages_dirty);
+int extent_writepages(struct address_space *mapping,
+ struct writeback_control *wbc);
+int btree_write_cache_pages(struct address_space *mapping,
+ struct writeback_control *wbc);
+void extent_readahead(struct readahead_control *rac);
+int extent_fiemap(struct btrfs_inode *inode, struct fiemap_extent_info *fieinfo,
+ u64 start, u64 len);
+int set_page_extent_mapped(struct page *page);
+void clear_page_extent_mapped(struct page *page);
+
+struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info,
+ u64 start, u64 owner_root, int level);
+struct extent_buffer *__alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
+ u64 start, unsigned long len);
+struct extent_buffer *alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
+ u64 start);
+struct extent_buffer *btrfs_clone_extent_buffer(const struct extent_buffer *src);
+struct extent_buffer *find_extent_buffer(struct btrfs_fs_info *fs_info,
+ u64 start);
+void free_extent_buffer(struct extent_buffer *eb);
+void free_extent_buffer_stale(struct extent_buffer *eb);
+#define WAIT_NONE 0
+#define WAIT_COMPLETE 1
+#define WAIT_PAGE_LOCK 2
+int read_extent_buffer_pages(struct extent_buffer *eb, int wait, int mirror_num,
+ struct btrfs_tree_parent_check *parent_check);
+void wait_on_extent_buffer_writeback(struct extent_buffer *eb);
+void btrfs_readahead_tree_block(struct btrfs_fs_info *fs_info,
+ u64 bytenr, u64 owner_root, u64 gen, int level);
+void btrfs_readahead_node_child(struct extent_buffer *node, int slot);
+
+static inline int num_extent_pages(const struct extent_buffer *eb)
+{
+ /*
+ * For sectorsize == PAGE_SIZE case, since nodesize is always aligned to
+ * sectorsize, it's just eb->len >> PAGE_SHIFT.
+ *
+ * For sectorsize < PAGE_SIZE case, we could have nodesize < PAGE_SIZE,
+ * thus have to ensure we get at least one page.
+ */
+ return (eb->len >> PAGE_SHIFT) ?: 1;
+}
+
+static inline int extent_buffer_uptodate(const struct extent_buffer *eb)
+{
+ return test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
+}
+
+int memcmp_extent_buffer(const struct extent_buffer *eb, const void *ptrv,
+ unsigned long start, unsigned long len);
+void read_extent_buffer(const struct extent_buffer *eb, void *dst,
+ unsigned long start,
+ unsigned long len);
+int read_extent_buffer_to_user_nofault(const struct extent_buffer *eb,
+ void __user *dst, unsigned long start,
+ unsigned long len);
+void write_extent_buffer(const struct extent_buffer *eb, const void *src,
+ unsigned long start, unsigned long len);
+
+static inline void write_extent_buffer_chunk_tree_uuid(
+ const struct extent_buffer *eb, const void *chunk_tree_uuid)
+{
+ write_extent_buffer(eb, chunk_tree_uuid,
+ offsetof(struct btrfs_header, chunk_tree_uuid),
+ BTRFS_FSID_SIZE);
+}
+
+static inline void write_extent_buffer_fsid(const struct extent_buffer *eb,
+ const void *fsid)
+{
+ write_extent_buffer(eb, fsid, offsetof(struct btrfs_header, fsid),
+ BTRFS_FSID_SIZE);
+}
+
+void copy_extent_buffer_full(const struct extent_buffer *dst,
+ const struct extent_buffer *src);
+void copy_extent_buffer(const struct extent_buffer *dst,
+ const struct extent_buffer *src,
+ unsigned long dst_offset, unsigned long src_offset,
+ unsigned long len);
+void memcpy_extent_buffer(const struct extent_buffer *dst,
+ unsigned long dst_offset, unsigned long src_offset,
+ unsigned long len);
+void memmove_extent_buffer(const struct extent_buffer *dst,
+ unsigned long dst_offset, unsigned long src_offset,
+ unsigned long len);
+void memzero_extent_buffer(const struct extent_buffer *eb, unsigned long start,
+ unsigned long len);
+int extent_buffer_test_bit(const struct extent_buffer *eb, unsigned long start,
+ unsigned long pos);
+void extent_buffer_bitmap_set(const struct extent_buffer *eb, unsigned long start,
+ unsigned long pos, unsigned long len);
+void extent_buffer_bitmap_clear(const struct extent_buffer *eb,
+ unsigned long start, unsigned long pos,
+ unsigned long len);
+void set_extent_buffer_dirty(struct extent_buffer *eb);
+void set_extent_buffer_uptodate(struct extent_buffer *eb);
+void clear_extent_buffer_uptodate(struct extent_buffer *eb);
+void extent_range_clear_dirty_for_io(struct inode *inode, u64 start, u64 end);
+void extent_clear_unlock_delalloc(struct btrfs_inode *inode, u64 start, u64 end,
+ struct page *locked_page,
+ u32 bits_to_clear, unsigned long page_ops);
+int extent_invalidate_folio(struct extent_io_tree *tree,
+ struct folio *folio, size_t offset);
+void btrfs_clear_buffer_dirty(struct btrfs_trans_handle *trans,
+ struct extent_buffer *buf);
+
+int btrfs_alloc_page_array(unsigned int nr_pages, struct page **page_array);
+
+#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
+bool find_lock_delalloc_range(struct inode *inode,
+ struct page *locked_page, u64 *start,
+ u64 *end);
+#endif
+struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info,
+ u64 start);
+
+#ifdef CONFIG_BTRFS_DEBUG
+void btrfs_extent_buffer_leak_debug_check(struct btrfs_fs_info *fs_info);
+#else
+#define btrfs_extent_buffer_leak_debug_check(fs_info) do {} while (0)
+#endif
+
+#endif